Yes, Air is matter. Matter is the substance or material of which all things are made. Matter has mass. Matter has volume. Air weighs very little, but takes up a lot of space. Air is still matter. If you put a balloon in an empty bottle and try to blow it up you cannot. This is because the air in the bottle has nowhere to go. But, when you poke a hole in the side of the bottle the balloon can be blown up, because it pushes the air out through the hole. This means that air is matter.